I have a many2one relationship that feeds a dropdown menu

I have a filter on the relationship, like this

domain=[('some_field', '=', True)]

this selects the records that appear in the dropdown menu

But if I want to create a new record from the dropdown menu, I'd also like the field "some_field" to be automatically set to True

How can I achieve that ?

I tried

context={'some_field': True}

but it seems it didn't work

Thanks